The design flexibility afforded by many thermoplastic compositions and their relatively light weights and corrosion resistances make them attractive materials for the replacement of metal components in many applications. However, thermoplastic compositions often possess an insufficient combination of stiffness, strength, toughness and/or other physical properties to satisfy the requirements of many of these applications. Semiaromatic polyamides, in particular, would be desirable materials to use in many metal-replacement applications as they can exhibit a roughly constant stiffness over a wide and useful temperature range for many applications, including automotive uses. The addition of fibrous reinforcing agents to semiaromatic polyamide compositions can produce materials having good stiffnesses, but this gain is often at the expense of the toughness of the resulting material. It would thus be desirable to produce semiaromatic polyamide structures having physical properties that rendered them suitable for use as replacements for metal components in various applications.
U.S. Pat. No. 6,644,722 discloses a molded article having a rigid support to which is attached a rigid hollow thermoplastic member. U.S. Pat. No. 5,219,642 discloses a structural thermoplastic composite material comprising a laminate of a fiber reinforced thermoformable crystalline polymer composite and an adherent layer of a second thermoformable polymer. U.S. Re 34,447 discloses crystalline polyamide compositions and laminates made therefrom. EP 1387760 discloses a method of production of a fiber-reinforced plastic component.